I'd recommend using the DIY style rigging, though I've found it much more practical to replace the stainless steel band with a tank strap and camband. Doing this you can use almost any cylinder with the rigging and it's fairly light to travel with.

If I can't source the right size bailout cylinder, I'll usually just slap the rigging on a 80cf ally and deal with that. If doing shallow non-deco stuff, I'll just rely on my onboard dil as bailout (yes, I'm aware many say this is inadequate so please don't tell me how foolish I am).